This application requests support for eight positions for physicians committed to a career in cancer research. The intent of the training grant is to provide in-depth didactic and project-oriented research experience for both physicians who have participated in clinical training programs related to cancer. Candidates will be sought primarily from the large pool of clinical trainees in surgery, medical oncology, pediatric oncology, and radiation therapy at the Massachusetts General Hospital and will work in research groups at the MGH and affiliated institutions. The program is based on the rapidly evolving model of multi-disciplinary, disease-based research and patient care at the MGH and the Dana Farber/Harvard Cancer Center, of which the MGH is a member. In this model, disease-based clinical programs in lung, breast, colon, and other cancers link to, and collaborate with investigators from basic and population science laboratories to expedite the translation of research findings into useful clinical applications. The core laboratories and clinical trials program of the DF/HCC, including dedicated core laboratories in molecular pathology for each disease program, are available to all investigators and their trainees in support of their research. In this disease-based model, all medical and surgical specialties participate equally in research planning and project development. Our wish is to train the next generation of pediatric and medical oncologists, surgical oncologists, and radiation therapists in the basic methods and concepts of cancer research, strengthening the ties between laboratory and clinic. Responding to the encouragement of our previous reviews, the current proposal seeks to expand and strengthen this concept of multidisciplinary training. Thus the proposal emphasizes participation of all specialties and research disciplines in the leadership and planning of the program, in the selection of candidates, and in the monitoring of the progress of trainees.